Antibiotic residues in chicken found by CSE’s pollution monitoring lab

Thursday, 31 July, 2014, 08 : 00 AM [IST]

Ashwani Maindola, New Delhi

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The pollution monitoring laboratory (PML) of the Centre for Science and Environment (CSE), the New Delhi-based research and advocacy think-tank, found residues of antibiotics in 40 per cent of the chicken samples it tested.

The think-tank’s recent study also concluded that Indians are developing resistance to antibiotics, and falling prey to a host of otherwise curable ailments. Some of this resistance might be due to the large-scale unregulated use of antibiotics in the poultry industry.

Chandra Bhushan, deputy director general, CSE, and head of the lab, said, “Public health experts have long suspected that such rampant use of antibiotics in animals could be a reason for increasing antibiotic resistance in India.”

“But the government has no data on the use of antibiotics in the country, let alone on the prevalence of antibiotic resistance. Our study proves the rampant use, and also shows that this could be strongly linked to growing antibiotic resistance in humans in India,” he added.

Test resultsPML tested 70 samples of branded and non-branded chicken, procured from various markets across Delhi and the National Capital Region (NCR). Of these, 36 samples were picked from Delhi, 12 from Noida, eight from Gurgaon and seven each from Faridabad and Ghaziabad from various markets.

Three tissues (muscle, liver and kidney) were tested for the presence of six antibiotics widely used in poultry - oxytetracycline, chlortetracycline and doxycycline (class tetracyclines); enrofloxacin and ciprofloxacin (class fluoroquinolones) and neomycin (an aminoglycoside).

So far, this is one of the biggest studies conducted in India to test chicken for antibiotic residues.

The residues of five of the six antibiotics were found in all the three tissues of the chicken samples. They were found to be in the range of 3.37-131.75µg/kg.

Of the samples found tainted with antibiotic residues, 22.9 per cent contained residues of only one antibiotic, while the remaining 17.1 per cent samples had residues of more than one antibiotic.

In one sample purchased from Gurgaon, a cocktail of three antibiotics (oxytetracycline, doxycycline and enrofloxacin) was found. This indicated the rampant use of multiple antibiotics by the poultry industry.

CSE researchers pointed out that antibiotics are frequently pumped into chicken during its life cycle of 35-42 days.

They are occasionally given as a drug to treat infections, regularly mixed with feed to promote growth and routinely administered to all birds for several days to prevent infections, even when there are no signs of it.

“Our study is only the tip of the iceberg. There are many more antibiotics that are rampantly used, but the lab has not tested them yet,” stated Bhushan.

What does it mean?The large-scale misuse and overuse of antibiotics in chicken is leading to the emergence of antibiotic-resistant bacteria in the chicken itself.

These bacteria are then transmitted to humans through food or environment. Additionally, eating small doses of antibiotics through chicken could also lead to the development of antibiotic-resistant bacteria in humans.

In a tele-conference, Dr Devi Shetty, cardiac surgeon and founder of Narayana Health, said, “Amongst people who came to the hospital to cure health-related problems, at least 10 per cent were found to have been infected with the antibiotic-resistant bacteria.”

To ascertain the linkage between overuse of antibiotics in poultry farms and antibiotic resistance in humans, CSE researchers reviewed 13 studies conducted by various government and private hospitals across the country between 2002 and 2013.

They found that resistance was very high against ciprofloxacin, doxycycline and tetracyclines. These are the same antibiotics that were detected in the chicken samples.

The problem is compounded by the fact that many essential and important antibiotics for humans are being used by the poultry industry.

In India, there is growing evidence that resistance to fluoroquinolones (such as ciprofloxacin) is rapidly increasing.

Treating fatal diseases like sepsis, pneumonia and tuberculosis (TB) with fluoroquinolones is becoming tougher, because microbes that cause these diseases are increasingly becoming resistant to fluoroquinolones.

Replying to a question in Parliament recently, health minister Dr Harsh Vardhan said that the number of multi-drug resistant (MDR) tuberculosis (TB) cases in the country has increased fivefold between 2011 and 2013.

Studies showed that one-third of MDR-TB cases were resistant to fluoroquinolones, which are critical for MDR-TB treatment.

The CSE study found two fluoroquinolone antibiotics (enrofloxacin and ciprofloxacin) in 28.6 per cent of the chicken samples tested.

With antibiotics losing their effectiveness, the world would need newer antibiotics. Unfortunately, no new class of antibiotics has hit the market since the late 1980s.

In the United States, which is one of the largest users of antibiotics for animal food production, more than two million people suffer from antibiotic resistance-related illnesses every year; 23,000 of them succumb to the diseases.

Annual healthcare costs due to antibiotic resistance are estimated to be as high as $20 billion.

No such estimates are available for India, but cases of high antibiotic resistance are emerging from across the country.

So what is to be done?Governments worldwide are adopting regulations to control the use of antibiotics. But only those countries have shown signs of improvement that have taken stringent actions.

The European Union (EU), for instance, has banned the use of antibiotics as growth promoters.

The World Health Organisation (WHO) recommended that antibiotics that are critical for human use should not be used in animals.

Countries have also set standards for antibiotics in food commodities.

CSE researchers pointed out that the poultry industry in India is growing at 10 per cent per annum. Poultry constitutes more than 50 per cent of all the meat consumed in India.

Said Bhushan, “India will have to adopt a comprehensive approach to tackle this problem. The biggest problem is the emergence of resistant bacteria in animals and its transmission through food and environment.”

“Till the time we keep misusing antibiotics in animals, we would not be able to solve the problem of antibiotic resistance,” he added.

“For India, therefore, the priority should be to put systems in place to reduce the use of antibiotics in poultry and other food animals,” Bhushan stated.

CSE recommended the following to the government:

Ban the use of antibiotics as growth promoters and for mass disease prevention. Antibiotics critical for humans should not be allowed in the poultry industry;

Antibiotics should not be used as a feed additive. The government should regulate the poultry feed industry;

Unlicenced and unlabelled antibiotics should not be sold in the market;

The government should promote the development of alternatives and good farm management practices;

Set standards for antibiotics in chicken products;

Set up systems for the monitoring and surveillance of antibiotic use and antibiotic resistance in humans and animals, and